Disclosed herein are thermally conductive foam products. The invention is useful for providing heat management in electronic devices.
Circuit designs for electronic devices such as televisions, radios, computers, medical instruments, business machines, communications equipment, and the like have become increasingly smaller and thinner. Smaller electronic components are being densely packed into ever smaller areas. Also, the increasing power of such devices has resulted in the need to squeeze more power into smaller space. Thus, manufacturers are continuously facing the challenge of dissipating the heat generated within such electronic devices
Accordingly, novel designs for thermal management, to dissipate the heat from electronic devices, have been developed. For example, U.S. Pat. No. 6,591,897 discloses a heat sink for electronic devices with a plurality of columnar pins, for conducting heat from a spreader plate, that are mounted on a top surface of the spreader plate. A foam block is mounted on the spreader plate and surrounds the columnar pins. The foam material, however, is used primarily for heat transfer rather than for compressibility
U.S. Patent Pub. No. 2012/0048528 discloses a compressible, thermally conductive foam pad that is coated, molded or extruded and filled with ceramic fillers, such as Al2O3 or BN (boron nitride) particles, in an amount of between about 20% and 80% of the total weight of the foam pad. The foam pad can be selected from various elastomeric materials, including silicon or polyurethane. Due to the thickness of the pad, air-filled through holes (vias) are provided in the pad to provide further compressibility. The presence of a plurality of vias provides for the compression of the normally incompressible product when subjected to an external force or load. It has been found that as the load on the thermal interface increases, the void volume decreases, resulting in increasing thermal conductivity with increasing load. The foam can have a thermal conductivity of at least 0.5 W/m-K.
Despite the variety of materials and designs that have been proposed for use in thermal management, as exemplified by the foregoing, it is apparent that there is a continued desire for new and improved thermal management materials for use by electronics manufacturers.
Accordingly, it is an objective of the present invention to provide an improved thermal management product for electronic devices and other applications. The product should have excellent heat transfer efficiency and heat dissipation in combination with conformability and compact size as necessary for a particular application. The product should also be capable of advantageous manufacture.